SWR will vary based on topography, wire orientation and use of ground or counterpoise. Step 1: Drill holes for and install the SO-239 or BNC connector, the stainless steel machine screw antenna connector and the ss machine screw ground connector. Feeling a bit too lazy to calculate that by hand, however, I wrote a A couple hours later when I sat down to do some more DXing, I made contact with a gentleman in Slovenia-my second European contact. This type of antenna is very easy to install because there is no need . 1 0 obj 10C) for the 10-80 m bands, or even 6-160 m: 17 ft (5.2 m) of twin-lead and 68 ft (20.7 m) of antenna wire (i.e., standard dimensions). /ModDate (D:20221212112042) Both were on 20 meters at 97 watts, Icom 7300. Re: 9:1 or 49:1 unun for end-fed long/random wire? Lengths to avoid are not always the same as This will be for an eyehook in order to provide strain relief for the radiator wire. STORE RFI Tips and Tricks This transformer is designed to be used with an end fed half wavelength of wire only. config file by typing gnuplot rw.gnu. Repeater Basics I sent him the link to the 49:1 unit to get his feedback. 3. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 | Mobile Phones & Communication, Radio Communication Equipment, Antennas | eBay! We recently found some good information about random wire lengths that you should and should not use. Bullet 50:450 (9:1) HF Unun, 1.8-61 MHz, 1500 Watts, End Fed Antennas. PDF Construction Details 49:1 Un-Un For End-Fed Resonant HalfWave Antenna The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0.05 . Hertz Antenna" shows in line 2 of the table that a similarly installed << HF Underground wiki Radio Hobbyist technical blogHFU Discord EuroPirate ChatPropagation DataTeamspeak Server, TDK CXA-2090 LCD Inverter Module New Old Stock USA Seller $19.99, Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night, Login with username, password and session length. Many hams have tried till they are blue in the face to install the random wire antenna that works on most; if not all of the HF bands with terrible results. The WSPR map is so dense it looks like the US and Europe are just big blobs of color. endobj Proudly powered by WordPress the program as I did, above, for my K1. and leave the unun on the ground. 1863 1.49 swr 3915 2.50 7200 1.80 14.332 1.29 18.130 1.07 21.300 1.40 24.950 1.30 28.400 1.37 This is a great antenna that is . Scott builds a compact random wire antenna with 9:1 Unun Multi-band end-fed - Nonstop Systems The following wire connections do not need to be made in the order I described. I purchased a MFJ-16010 Random Wire Tuner and an LDG RU 1:1 unun. Tools Let the now free end of the short wire hang down from the toroid. This homebrew 49:1 impedance transformer is the heart of any EFHW antenna you will build, most of the time. Cut the center conductor wire (free untwisted end of short wire) of the unun to the correct size, scrape the enamel insulation off of the free end with a box cutter, and solder it to the SO239 connector. Ask Elmer installed, it is a compromise antenna but great for portable use because Again, the bands are USA, so change them >> So I just wanna say thank-you!! So for example 80m could range in length from 120 to 133 feet. https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/. which got me thinking. (The numbers aboveare a great start, thanks to Jack and Mike! endobj Repeater Builders It will be good for 15m, and 10m. an auto-tuner at the base vs. the same antenna fed a 4:1 balun wound with 75 ohm coax on two separate type 43 ferrite cores and a remotely sited tuner fed via 200ft of low loss LDF2-50 coax vs. a broadband antenna of the same element length. Let's have a look at a few details on how to build a 49:1 impedance . is helpful if you're in a hurry to get on the air, read up on the topic 2 0 obj You have to give up a band or two, like 60m and 6m, as Dimensional Drawing of Standard Enclosure, 1:1 Common Mode Choke / Noise Suppression, Core Material Selecton for Baluns and Ununs, Antenna Matching Problems When Using Ladder Line or Open Wire Feedlines, Model 4932 - 4 & 9:1 Unun 1.5 - 54MHz - 2kW, Model 49130 - 49:1 - 80-10m EFHW - 200 watts, Model 64131e - 64:1 & 49:1 - 80-10m EFHW - Up to 1kW, Model 4116 - 4:1 Hybrid Balun 1.5 - 54MHz 3kW, Model 9130sw - QRP 9:1 Unun 1.5 - 54 MHz - 300 watts, Model 1115d - Max Choking 1:1 Balun, 1.5-54 MHz, 5kW. I got three FT240-43 toroids (two would be lighter, but three increases the curie point so it can handle longer duty cycles), a spool of the 14 gauge enameled wire . Contact >> The table below represents half wave lengths and multiples that you DO NOT WANT TO USE! Two pieces of 14 gauge enameled wire (e.g., Thermalese), one short piece (about 1 foot in length) and one long piece (about 7 feet in length). <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 80m up, W3EDP's 84' antenna, 17' counterpoise is probably the way to go. This undesired reflection of RF power back toward the transceiver is identified as a high voltage standing wave ratio (VSWR or SWR). <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> unavailable, a random wire can save the day, but it is important to The 49:1 impedance transformer will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. W3EDP's results in the above referenced it is easy to pack and easy to install. Powered by BigCommerce. Random wire lengths you should and should not use! I used the RigExpert Zoom AA-55 to test VSWR of the 49:1 unun impedance transformer. LDG Electronics RU-9:1 Unun RU-9-1 - DX Engineering A VSWR sweep of the unun after adding a 100pF capacitor shows an SWR <5:1 from 160M to 10M. The 49:1 unun with 3000 ohms of resistance shows a VSWR under 10:1 from 160M to 15M, and less than 3:1 from 80M to 20M. document.getElementById("copyright_year").innerHTML = new Date().getFullYear(); Home-brew End-Fed 49:1 UnUn. - KA9QJG Repeaters The major point of this message is to tell you that approximately 20 minutes after I connected the balun unit to the antenna, I made contact with a gentleman in Italy-my first European contact!! The 9:1 may work best with that length wire and a tuner, but some say that length is undesirable for the hf HAM bands. He was so impressed that he purchased a 9:1 unit from you, his will be delivered Saturday. The WorldwideDX Radio Forum was originally established in 2001. How to Make a Balun or Unun : 3 Steps - Instructables random wire should use 423/f. In stock . << The Short Answer Would Be That an UnUn Is a "UN balanced to UN balanced" matching transformer. We hoisted the free end of the antenna wire approximately 30 feet into a tree. Quantity: Sold individually. The length of enamelled copper wire per winding for the T-200-2 powdered iron toroid core is determined by length per winding = 50mm per turn plus 250mm tails. Wait a few minutes for glue to set. , Most matching problems occur when the antenna system So for 80 meters (say 3.525 MHz) this gives you about 133' of wire. here are values for CW portions of the USA End Fed Antennas. WwS`8o}=n,pjhzRa]Ju/Ru ni4=UvZ:u9*@ Xz+zZcXm}i[Z;Z>.u!*eQVjucXeqYZnSJu)U[n>>KXzZ.Lz sqxcGj]%q}i6=-?YTlnZXV6}=U >5`ZNxChzRa]JU.6TVr6a] Site Map When used with the stated Balun Designsis now offering a low power alternative for those who want to use an End Fed Half Wave for portable or temporary installations. x 4 in. It's an efficient way to get all the multiples If you want a single band portable antenna you can mount pretty much however, look up this design. End Fed Long Wire Antennas - Palomar Engineers At multiples of half wavelengths of the This Balun Designs unit is replacing an MFj 1982 HP EFHW balun that was DOA when it arrived last May. 49:1 EFHW Antenna 40-10M 100W - M1ECC-Antennas The counterpoise wire, This transformer is designed to be used with an end fed, Approx. x@ Thus a 1/4 wave for 20m@16ft, 40m@33ft as examples are not going to work. Random wire length for 9:1 unun - fairlawnarc.groups.io The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built orbought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. X:nzf4p:t;r }~_HOZcX:^$* J^XZuu|"nX/Wkw0hA>y1(z2+v_Xzu[/:^$*m*>hk_:+c{ The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. For example, I use this 8010 EFHW at home, too. However, the radio didn't tune up very well on 15 meters. Free Postage. /* Ad banner 160 x 600 */ Product Reviews Anyway, an old friend mentioned 'MyAntenna.com' but they were closed for the summer. This is a 4:1 Current Balun.That means it can match a 200ohm antenna to a 50 feed line. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. End Fed Half Wave Antennas - Elgin Amateur Radio Society bands as possible. When do you use a 1:1, 9:1 or a 49:1 balun? doing the initial 468/f on C and D scales. I actually did this first and before the connector was bolted to the box. EFHW unun Resonant Long Wire 49:1 Transformer With BNC or SO-239 Power handling is 100 watts CW / SSB & 25W Data modes. You will also need a half-wavelength length of wire (14 or 12 gauge typically) in order to construct an antenna radiator for whichever ham band you choose. 3 0 obj Legal Stuff This is a followup video to #344 where I assembled the 49:1 UNUN kit from HF-Kits / ARRL. Wire lengths for the 4:1 ratio in models 4130, 4132, 4134, 4932 and 4935. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. The length should be calculated based on the lowest frequency to be worked. stream It is used fornon-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed1/2 Wave Multiple Length Wire Antenna. 1. Well then you need to choose a wire length that is at least 1/4 on 40 meters, and doesn't fall on any of the 1/2 multiples for ALL the bands between 40 to 10 meters While you could certainly calculate the lengths to avoid using the standard formulas, and then make a chart, the section below may be what you are looking for. I included the tools I used to analyze the transformer as well; this is only necessary if you are interested in analyzing your project. What Is an End-Fed Half-Wave (EFHW) Antenna? - OnAllBands That type of wire antenna could be lower than 50 ohms at some frequencies and over 2,000 ohms at . In another life, I could have been a telephone engineer. << Several ways exist to bring the wire's high impedance feedpoint closer to the desired 50 ohms, including use of a 49:1 or 64:1 unun, which eliminates the need . PDF portable multi-band End-Fed Half Wave (EFHW) antenna for 40-10m You will note that when comparing my results with VE3EED that some of the results are a bit different. A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. /Height 752 Advertising Info Humor Code Practice Update guys:made the unun,the antenna was extended to about 37m length,and I added a counterpoise which is about 10m.The whole thing is much higher in the air,compared to where it was before. Recommended wire lengths for Unun Balun - Webclass.org All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulatorsand a little time. End Fed Antennas - Elgin Amateur Radio Society When you're antenna (or radial) length's an odd multiple of the operating freq, you may not need a balun or even a transmatch. End-fed wire antenna lengths - Amateur Radio Stack Exchange (Also note that here may be instances where the suggested lengths may not work exactly due to the many variables in the surroundings of the antenna, wire length variances, your tuner, it's height above ground, it's construction, etc. Balun Designs. Q Random Wire Antenna Lengths - University of Delaware Change the program to use 423 if desired.) google_ad_slot = "1982258389"; 9 0 obj used by hams for dipole lengths. However, the list has been revised and is good for wires as long as 500 feet. I did not want to put the transformer in the housing until I tested it. It is optimized for 3.5/7/10/14 MHz but will work reasonably well on all amateur bands from 80 meters thru 10 meters with a 135 foot length of wire and a short connection to ground. Using a 49:1 transformer shoot for the best 50 match @ appx 2450 load over your working frequency bands. Upon further research, I remade it tightly twisting those two separate wires together, just as it shows in archjeb's picture, and it worked surprisingly well. This article details the construction of the transformer. presents an extremely high impedance to the tu Ham Hints Use a slide rule! /Type /Catalog It is used for non-resonant verticals like 43 foot or 33 foot Or Wire antennas like an End-Fed 1/2 Wave Multiple Length Wire Antenna. something as high as you can find. 40-10m with a 49:1 Unun. /Parent 3 0 R Midi Music JC[ d8O[UKKQ{yZ{G 'Upno_*~8uo a@G`' zxUHXW&`}mEp`?i0 oE:N0-/t"t.-? transmit frequency the impedance is so high that tuners in most rigs 4 0 obj uR5ucE`_aksLjYT=hzRa]JucX7d}|'}`XRa>X The kit includes the parts needed to construct a 49:1 impedance matching network, which will transform the impedance to 50 Ohms, which will suit most transceivers. 7 0 obj Start winding the toroid with the twisted wires at loop #1 (see schematic below). 9:1 Unun EF Random Long wire matching Transformer with BNC or SO-239. endstream endobj startxref The novel thing was that I only built it the day before and it uses a Coghlan camping washing line spool with the string taken off and about 21m of wire wound onto it. Random Wire Antennas - Best Lengths To Use For Random Wire The QRP End-Fed Half-Wave Antenna 49:1 Transformer Building a great impedance transformer for Ham Radio end-fed wire antennas. End Fed Half Wave 40-10 Wire Antenna - N6DOZ The magic lengths to use with the End Fed longwire is 29, 35.5, 41, 58, 71 and 84 feet I use a 29 foot wire with my PackTenna 9:1 balun for 40m-10m and then add a 28 foot length for better coverage on 80m when needed. You can get good loading and low swr on sometimes 2 or 3 bands, but one or more of the bands thatyou want, just will not cooperate with an swr that can be adjusted with the "tuner". My commercial EFHW is 130 feet long for 80 and up, and my 40 meter homebrew antenna is about . 6 0 obj Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. The matching unit The impedance at the end of a half wave antenna is somewhere between 2000-5000 Ohms. Here is an ARRL google_ad_client = "ca-pub-9377297764300878"; (Also check out AB3AP'Swebsite and say thanks for sharing his skills. I'll get a 9:1 unun,and use a suggested random wire length to avoid half-wave and it's multiples then,that sounds like the best things I can get out of this setup. /Producer (XnView, http://www.xnview.com) >> That is the 10th multiple of a half wave on 15 meters. Then verify it with your installed antenna and SWR measurements. SSTV The vertical (y-) axis shows the VSWR and the horizontal (x-) axis shows the frequencies. We have also installed an additionalstud which can be used for a separate counterpoise wire rather than forcing the use of the feedline's coax shield. It may not display this or other websites correctly. Start winding the Matching Auto Transformer, each pass through the center of the core equals one turn. | This is considered a random wire end fed antenna, not to be confused with a half wave end fed antenna which uses a 49:1 or 64:1 unun and a wire that is a half wave length. NEMA rated 4x marine grade junction box for outdoor installations. While I have not done so yet, I plan on gluing the test cap to the back of the junction box. You have to stay away from a half wavelength on any frequency. 1:64 vs 1:49 balun for an end fed?? : r/amateurradio - reddit Re: 49:1 transformer for EFHW antenna - groups.io $1YacO5Q}YC\>qZ } Turns 1 & 2 are primary windings (the short wire). recommended on VE3EED's page because I use all halfwave I've made contact with several folks across North America in my 6 months as an amateur but getting to Europe flipped a switch and I'm afraid this amateur radio thing is going to be addicting. % stream I imported my spools from the US, but I have seen them on Ebay in the UK. I have not done this yet. Use with other lengths can potentially damage the transformer depending on power level in use. (Also note that here may be instances where the suggested lengths may not work exactly due tothe many variablesin the surroundings of the antenna, wire length variances,your tuner, it's height above ground, it's construction,etc. Some of these numbers are too close to squeeze in between them. 40-30-20-15m bands for my 4 band Elecraft K1 qrp rig. google_ad_height = 600; A so-called random wire antenna is an end fed antenna. Downward impedance transformation by factor of 49. For reasons that I do not understand, adding a capacitor between the coax conductor wire (untwisted free end of short wire) and the ground (twisted free ends of long and short wire) can increase the functional bandwidth of the antenna on the higher HF frequencies. hb```YloD@(aKI V!}g@~}%Q/[[~_=Wy-:O)x[~hs/~SGeG _QE C6q %r q Attaching a counterpoise wire to the common point of the auto-transformer provides the antenna radiator something to push against rather than the coax shield. Building on the original 1:1 design by Dr. Jerry Sevick, this balun has two (2) cores in a stacked Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Decrease Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW, Increase Quantity of Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW. program or two to do all the dirty work. Lowest Band of Operation: 160 meters Highest Band of Operation: 10 meters Additional Information LDG Electronics RU-9:1 Unun Theme: Newsup by Themeansar. Post Reviews Because I had some spare Cu-Wire I wound another 1:49 Unun on a smaller FT-140-43 toroid and tried different capacitors between feedline and ground (to compensate for the 10m band). You will also need a half-wavelength length of wire (14 or 12 gauge typically) in order to construct an antenna radiator for whichever ham band you choose. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. 49:1 UNUN Transformer 2 Kw 160 - 40 m - Wire Antennas Simple End Fed Half Wave for 40m (and how it works) Multiples are on C and 9:1 Unun 1.5-54MHz 2kW 9132S. endobj Experimenting with 1:64 and 1:49 end-fed antenna Ununs on - reddit Mike ab3ap, Editors note: Many thanks to Jack, VE3EDD (SK)and Mike, AB3APfor sharing their math and computerskills with us. =======================, More on Random Wire Lengths from Mike, AB3AP (06-29-2012), I was surfing around Hamuniverse.com and found thIs page on random wire antennas: Model 49131 - 49:1 - 80-10m EFHW - Up to 1kW - Balun Designs Following the directions exactly as specified (0.47wl / 0.05wl matching counterpoise) and drilling two weep holes in the appropriate position, I had a 10 meter EFHW antenna up in less than ten minutes. 35. Swr usually is all over the place and the tuner will just not do it's job. It is important to use a counterpoise. Odds are that most lengths are fine though, so the easiest solution is to pick a length based on something else (like, the room you have available) and if you get unlucky, roll the dice again. I used 2000 and 1000 ohm resistors in series connected to the proper unun wires with alligator clips for a total of 3000 ohms. This may not be relevant to HF stuff, but the antenna I use for NDB reception has a 400:1 transformer (20:1) turns ratio. If you want all the bands from stream good show chuck, you said ya picked up a 430, did i tell i fried the 0ne i got from you, can anyone point me in the direction of a 2 pill schem for the HG 2879? endobj Par EF 20 and par EF 40 (I realize for 17m I would prob just add that band to a 49:1 balun) That's that my question is. <> /Type /Page Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. 75/80 METER RESONATOR KIT FOR THE UJM-EFHW-40-10 200W 40-10m ANTENNA You also the C code, in Matlab or Octave get a plot by simply putting the 748 0 0 752 0 0 cm REVISED: 16 19 22 26 32 33 38 44 46 48 52 64 65 66 76 78 80 88 92 95 96 99 104 110 112 114 123 128 130 132 133 138 144 152 154 156 160 165 171 176 182 184 190 192 195 198 208 209 220 224 228 230 231 234 240 242 246 247 256 260 264 266 272 276 285 286 288 297 304 308 312 320 322 323 325 330 336 338 342 352 361 363 364 366 368 369 374 380 384 390 396 399 400 414 416 418 429 432 437 440 442 448 455 456 460 462 464 468 475 480 484 494 495 496. My homemade 49:1 EFWH with a 60 wire (cut for 40M) would do just fine! Computer Help He used 300 ohm twin-lead and a 4:1 UNUN, with a 1:1 current choke between the UNUN and the coax to the tuner and transceiver: The full-size "flimsy" (ref. Superglue 2 toroids together. The short piece is for the primary winding of the transformer, and the long piece is for the secondary winding of the transformer. /Length 10 0 R A 49:1 would match 50 ohms to about 2,450 ohms and a 64:1 matches to 3,200 ohms, typical of a 1/2 wave end fed. Note: My (A to B) length was 6 inches. /Subtype /Image So, if you connect a length of wire that presents an impedance of about 450 to the input, you'll get an impedance of about 50 on the output. About Hamuniverse This is to avoid the antenna radiator from acting like a resistor, and thus instead of radiating radiofrequency energy produced by the transmitter, sending it back down the coax toward the transmitter. << END FED "RANDOM WIRE" HF DIPOLE 9:1 ANTENNA RELACEMENT ELEMENT ONLY $28.99 Save up to 6% when you buy more. Drill another hole in the same side as the antenna radiator wire mount hole. Just an FYI that I thought you might be interested in. For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, We have also installed an additionalstud which can be used for a separate counterpoise wire rather than forcing the use of the feedline's coax shield, ttaching a counterpoise wire to the common point of the auto-transformer, provides the antenna radiator something to push against rather than the coax shield. #347: Quick test of the 40m Halfwave End-Fed antenna using a 49:1 2. uR5I5z G^u2`j[}+sy9 The length should be calculated based on the lowest frequency to be worked. %PDF-1.7 8 0 obj << About Batteries random wire page. A Balun is used to match a balanced line to an unbalanced line. I connected the free twisted end of the short and long wires (the ground) the chassis wire (ground) of my homemade testing jig with alligator clip. I have used the 49.2 ft (15 Meter) length of wire on vacation with both automatic tuners and an MFJ Model 16010 tuner with good results for 40, 20, 17, and 15 Meter operation. 3 0 obj When used with the stated lengths shown in thetable below, the 9:1 ratio will Based on the success of our model 4932, this 5kWconfigurationisalso perfect for matching both long and short length wire antennas for multiband use. endobj Meet 'Balun One Nine', a small, cost-effective balun. Hi guys,not really hfu related,but I tought I might ask here as I have my account. endobj As an example, a 28-31 foot wire will typically allow 40 thru 10 meter coverage and a 43-50 foot wire will provide access to 80 thru 10 meters. frequencies for your country or favorite modes. I only used two screws instead of four.